Heating unit for electrically-heated tools



F. KUHN, L. H THOMAS, AND J. G. SPIESS.

HEATING UNIT FOR ELECTRICALLY HEATED TOOLS.

APPLICATION FILED MAY 27, 1-920.

Patelited Feb. 28, 1922.

attouuqa UNITED STATES PATENT OFFICE.

FRANK KUHN, LAWRENCE H. THOMAS, AND JULES e. srnsss, 0F nirrnom, MI

ASSIGNORS TO AMERICAN ELECTRICAL HEATER COMPANY,

IGAN, A CORPQRATION OF MICHIGAN.

036 DETROIT, MICH- HEATING U NI'I FOR ELECTRICALLY-HEATED TOOLS.

Application filed May 27,

To all whom-2'25 may concern Be it known that we, FRANK KUHN and Lawrence H. THOMAS, both citizens of the United States of America, and JULES G. SPIESS, a citizen Of the Republic of France, having taken out first citizenship papers in the United States of America, all residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Heating Units for Electrically-Heated Tools, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to heating units for electrically heated tools of that type in which the terminals are carried outward through a hollow handle of the tool. It is the object of the invention to provide an armored heating unit which also protects the terminals, and to this end the invention consists in the construction as hereinafter set forth.

In the drawings:

Figure 1 is .a perspective view of the unit;

Figure 2 is an enlarged longitudinal section through the terminals, showing the protecting means therefor;

Figure 3 is a cross-section of Figure 2;

Figure 4; is a plan view of one of the armor plates.

The heating unit is of that type in which the resistor is wound or bent to extend in a zig-zag course about a flat core, said core and resistor being then enclosed by outer insulator plates and a metallic armor adja cent thereto. Reference is made to the ent to F. Kuhn and J. A. Hand 1,2883% showing the general arrangement of resistor upon a flat core. lVith such constructions it is usual to allow the terminals to pass outward from one end and in the incorporation of the unit into an electrically heated handled tool, it is necessary to thread these terminals through the hollow handle. The terminals are very delicate and easily injured, so that care must be exercised in the installing of the unit.

With the present construction the terminals, as well as the resist-or, are armored and this armor is formed of tube segments respectively integral with the opposite armor plates for the flat unit. in detail, A is the unit having the armor plates B and C on opposite sides thereof clinched together Specification of Letters Eatent.

Patented Feb. 28, 1922.

1920. Serial No. 334,514.

at their edges by the return-bends D. Each of these armor plates is provided with an outwardly extending shank E and these s1 malts are pressed to form the segment of a, tube cooperating with the corresponding portion f the other plate to enclose the ter mnnls. T he terminals are formed by end portions of the resistor as indicated at F which are held out of contact with each other by a series of cylindrical insulators G hav ing separate longitudinal passages therethrough. These insulators will fit within the tubular shanks E and during assemblv ma be easily threaded upon the terminals and slipped within said tube.

With the construction as described. when the unit is mounted in the tool, the tube F. can be readily inserted through the hollow handle, which will carry the ends of the terminals into position for connection with the external circuit.

What we claim as our invention is:

l. A heating unit comprising a flat insulated resistor, terminals leading therefrom, an rmor comprising plates clamped u ion opposite sides of said insulated resistor, ano integral extensions of said plates forming segments of tubes for enclosing said terminals.

An electrical heating unit comprising a flat insulated resistor, terminals leading therefrom, an armor comprising fiat plates arranged upon opposite sides of said insulated re or, and integral extensions of said plates forming complementary segments of a tube for enclosing said terminals.

an electrical heating unit comprising a flaw insulating resistor with terminals leading therefrom, a series of insulators sleeved u on said terminals to hold the same separate, and an armor comprising flat plates secured upon opposite sides of said insulated resistor, and extensions of said plates forming complementary segments of a tube for embracing said terminals and insulators thereon.

el. An electrical heating unit comprising adiat insulated resistor having terminals leading therefrom. insulators sleeved upon said terminals and holding the same from contact with each oth r, an armor comprising flat plates upon opposite sides of said insulated resistor and having their edges clinched together, and extensions of said plat-es forming complementary segments of integral segmental extension for receiving tubes for embracing said terminals and insaid terminals.

sulntors. In testimony whereof we affix our signa- 5. An electrical heating unit comprising tures.

:1 fiat insulated resistor with terminals lead- FRANK KUHN.

ing therefrom, and an armor for inclosing LAW'RENGE I-l. THOMAS.

sail'l resistor having a flatportion and an JULES G. SPIESS. 

